Fig 2.

Inhibition of p38 MAPK in endotoxin-responsive cells blocks proinflammatory cytokine synthesis in response to TLR4 stimulation. Endotoxin-responsive THP-1 cells were pretreated for 1 h with 10 μM of the p38 MAPK inhibitor SB203580 and then stimulated with 1 μg/ml of LPS for the indicated times. (A) Expression levels of p38 and phospho p38 MAPK proteins were measured by Western blot analysis. (B) Cells (with the culture supernatants) were harvested and lysed, and then levels of TNF-α and IL-6 proteins were measured by enzyme-linked immunosorbent assay (ELISA). Data are means ± SD of three experiments. *, P < 0.05 compared with treated cells. DMSO, dimethyl sulfoxide.